Natural Resources

County-wide Natural Systems

Integrated water planning, municipal water regulations, multi-municipal planning

There is a need for integrated water and wastewater planning at the local or regional level.

The water balance

The water balance is being altered by changes across the county's land surface, including impervious surfaces and the overuse of lawn. Flooding and drought remain ongoing concerns, especially with climate change.

Wastewater treatment

There has been a shortfall in outreach to inform the public that treatment techniques such as spray and drip irrigation are safe and good for the environment. There is a misperception that spray and drip fields are toxic, when in fact they are safer than stream discharge. Spray irrigation systems could be used more extensively to promote infiltration.

Overlapping programs regulating water resources by state and federal agencies are highly technical and can be confusing for the local planners and elected officials who must implement them.

Overlapping requirements

Regulations regarding floodplains, waterways, hydric soils and wetlands all relate to the same riparian corridors, yet these regulations are often enacted separately at different times. The Pennsylvania Department of Environmental Protection (DEP) MS4 program applies to 60 of the county's 73 municipalities and eventually will apply to all of them. This is even more complicated by the fact that MS4, NPDES and TMLD requirements have not yet been fully completed, so local officials do not know what to expect.

Complex regulations

The National Pollutant Discharge Elimination System (NPDES) applies to all municipalities in Chester County. It is rather complex and not always understood by local officials. There are also Total Maximum Daily Load (TMDL) pollution requirements in NPDES permits, but many people do not understand the connection between them. Most municipalities are not equipped to address non-point source pollution. Furthermore, Pennsylvania Act 167 stormwater management plans have been costly and slow to be implemented and the DEP often requires specific language which is highly technical and difficult for local officials to understand.

Municipal implementation

Municipalities have responsibility for implementing a variety of water resource regulations that are not directly related to land use regulations. Pennsylvania Act 537 municipal wastewater planning does not include requirements to address the availability of water supplies for projected wastewater demands.

Regional initiatives

Public water withdrawals can be regulated by the state, the Delaware River Basin Commission or the Susquehanna River Basin Commission, but these regulations are often not fully understood by local officials. Chesapeake Bay Tributary Strategy nutrient reduction and runoff management impacts southwest Chester County.

Scientifically important natural resource issues are not always communicated to planners and local officials.

Biodiversity and resource inventories

Biodiversity is often viewed as an idealistic long term goal, but it is more prudent to regard it as an ecological health index. When biodiversity is low, that should be seen as a red flag requiring short term action. For example, diversity of aquatic insects and micro-invertebrate reflect not just animal populations, but also water quality conditions and the conditions on the watershed landscapes. There are extensive wetland complexes in Chester County that have not been mapped as such and are largely unknown.

Legacy sediments

Legacy sediments are previously eroded soils which may contain contaminants that were deposited in floodplains and stream channels long ago. Legacy sediments can be eroded and released as contaminants down stream. These sediments often come from the back-up behind numerous small mill dams that existed in past centuries and are long forgotten. As a result, these sediments may appear to be part of the natural landscape, and may even be covered with historic buildings and trees.

Land Resources

Globally significant agricultural soils are being consumed by development and eroded by traditional farming practices.

The soils and topography of most of Chester County are generally ideal for agriculture. Good soil, abundant rainfall, and close proximity to major cities and seaports along the east coast make the county well suited for the business of agriculture over the long term. Much of western Chester County is underlain by the Piedmont soils of southeast Pennsylvania. These soils, which also cover much of York and Lancaster Counties, are regarded as globally significant, especially since they do not require major irrigation infrastructure. However, these soils and topographic conditions also make the county well-suited for development. As a result, these high quality soils are under an ongoing threat. Preservation of productive agricultural soils, and the sustainable local food source it provides, is both a local and national economic issue. Soils are a complex underground natural ecosystem, like above-ground forests and wetlands.

Soils require protection and management if these resources are to be sustained. Not all farmers have voluntarily installed best management practices to control erosion and sedimentation.

Natural resources can be unintentionally degraded when resource protection regulations are not comprehensive.

Municipal ordinances typically identify which soil types will get the highest protection priority. Realistically, not all soils can be protected. For example, if farmland is protected, then forest soils might end up getting developed, and vice versa. These local choices can pose regional impacts. Soil instability at headwater locations can impact flooding and water quality downstream. In Chester County, erosion can alter water quality in the Delaware and Chesapeake Bays. Degraded water quality in limestone areas such as the Great Valley can result in increased sinkholes and subsidence that alter the flow of streams.

Natural resources and unique habitats are being lost in Chester County, primarily through small and unintentional impacts.

With the rise in land prices in Chester County, developers are now building on lands containing resources that are sensitive to earth disturbance, including steep slopes, woodlands, and floodplains. As development encroaches upon these sensitive areas, there is a need for development design to protect these resources. There is a need to recognize the value of undisturbed native landscapes as more than just a location for scenic view sheds.

Biotic Resources

Vegetation, fauna, wildlife habitat, and migration corridors

The county's forests have become degraded and need to be restored and managed on a regional basis, but are currently managed on a municipal-basis.

Ongoing management

The county has many forested open spaces and riparian corridors. The ongoing management of vegetation, however, is not always considered in natural resource planning. Municipalities manage the open spaces within their borders, but rarely take a regional approach. Similarly, greenway planning does not always follow a regional approach, and the very term "greenway" is often defined differently by different entities. There is a need in Chester County for definitive mapping of forests to assist in this planning effort.

Threats to forests

The county's remnant forests continue to be degraded and cannot regenerate without assistance. Deer over-browsing makes it impossible to reforest or restore habitat in certain parts of the county, especially in our urbanized areas. Forests are also being degraded by invasive plants. Wooded hilltops are under threat from developments in search of a view. These impacts have especially hurt interior forests (a depth-to-core of 300 feet or more). There is a need to protect this type of forest in order to maintain forest biodiversity and health.

Restoring existing forests

There are two major forest stands in Chester County. First, the Hopewell Big Woods area of northern Chester County has 15,000 acres of contiguous forest and is one of the last major woodlands in the Piedmont Region. Second, the Serpentine Barrens in southern Chester County are a unique forested habitat. These barrens host a fire-dependent ecology that supports globally rare plant species, but controlled burns are not permitted in some locations.

Ecological degradation is increasing as a result of the introduction of non-native vegetation in the built environment.

Lawn and non-native plants

Throughout all parts of Chester County, urban and rural, there is a spreading threat of non-native plants, including planted conventional lawn grasses. Existing non-native street trees serve as invasive plant seed banks, and many commercial nurseries still sell invasive plants. Non-native cool-season grasses like Kentucky bluegrass are becoming too abundant, impacting runoff, and decreasing wildlife habitat. The county's abundant wetland habitats are mostly small and in riparian buffers. They are often overlooked and tend to be mowed like lawns, eliminating their many economic and community values. Landowners tend to mow or permit grazing along stream banks, yet these areas are recommended as no-mow zones in Watersheds.

Managing vegetation

Local ordinances that protect natural resources can be rendered ineffective without proper vegetation management. Steep slopes need to be vegetated in order to provide the valuable function of controlling runoff. The installation of lawns and ornamental trees is typically not ecologically sound because it does not restore the appropriate woodland ecology that is native to the county. Hedgerows need to be preserved as living historic structures that provide shelter and corridors for wildlife. There needs to be an integrated approach to vegetation planning. Selective replanting and ongoing maintenance are just as important as tree removal.

Appropriate tree plantings

Municipal ordinances typically do not consider tree design and function at maturity. Trees are often planted too close together. Similarly, street trees can be too large or fast growing, and so are inappropriate. The county's utility corridors are currently a haven for non-native vegetation, but could be reconverted to native grasses and shrubs.

Regional management plans are needed for animal populations that are impacted by land development or that pose threats to public health, traffic safety, agriculture, or habitat restoration.

Deer overpopulation

Deer overpopulation is a public health and safety issue that will remain over the long term of this plan. The rise in deer population is also heavily impacting orchards, nurseries and the ecology. Deer browsing in some areas make riparian buffer and forest restoration impossible. Deer and car accidents are a growing public safety issue.

Protecting habitat

Managing wildlife requires the management of habitat. There are "critical species" throughout Pennsylvania, not just preserves. Bog turtle habitat plays a role in land use and comprehensive planning. While there is no regional plan in place to restore them, research is being done on this issue.

Maintaining fisheries

Chester County has the potential to improve its fisheries and reap economic benefits. The health of the fish ecosystem is related to the ability of anglers to have access to catch fish. When anglers do not have stream access, there are fewer opportunities for anglers to observe water quality and fish health conditions.

Wildlife conflicts

Protected open space attracts wildlife, but there are conflicts when large animals venture into the developed areas. Bobcats and beavers are returning to Chester County, and black bears might reappear as they have in counties to the north and west. There are currently no specific regional policies regarding how to interface developed areas and "mega-fauna". The Game Commission's mission is limited to managing mega-fauna in a wilderness setting.

Meadow and wetland habitat

Municipal weed and mowing ordinances can potentially result in health issues. Some municipalities have ordinances that prohibit tall grass in lawns or seasonal mowing. These ordinances are often justified to control vermin even though scientific literature states that rats are not attracted to tall grass. Cutting wetland plants decreases the population of wetland predator species, such as bats or birds that eat mosquitoes, and create ideal Canada Geese habitats. Lyme disease, West Nile, and other vector diseases require animal control.

Locally important wildlife issues and ongoing wildlife management are often overlooked because emphasis is placed on issues that require permitting.

Economic benefits of wildlife

An important part of the county's tourism base, including Valley Forge and Longwood Gardens, is based on the county's natural heritage, which includes wildlife. A sterile field or forest (which has no significant wildlife) is less attractive to potential users and reduces interest in destinations such as state and county parks. Not only does wildlife access impacts tourism, it also impacts real estate since properties near popular parks have a higher value.

Wetlands are productive habitats

Wetland habitats are especially important to wildlife since even upland animals use streams as a drinking supply. Therefore, pollution and degradation of wetlands impacts adjacent habitats. Wetland species propagate wetland plants, which in turn purify surface water and reduce flooding. Aquatic macro-invertebrates (small, but visible water dwelling animals) are an important but often overlooked animal community. Water quality is measured by the biodiversity of aquatic macro-invertebrates.

Endangered species

The bog turtle is the most well-known endangered species in Chester County. Protecting this species requires taking a wildlife community approach to their habitat, and not just focusing on them as individual species. There is also public confusion as to what constitutes an Important Bird Area (IBA) and what that designation means.


Fisheries are important to selected areas of Chester County. Fish populations in the county are said to generate nearly $1 million to the county economy annually. However, fisheries have dwindled throughout the county due to both conventional and thermal pollution. Thermal pollution increases algae, which reduces aquatic wildlife. PCB pollution also hurts fishing because anglers cannot eat the fish they catch, which encourages them to fish elsewhere.

There are insufficient mechanisms in place to restore degraded habitat and reduce the effects of habitat fragmentation.

Migration routes

Selected areas of the county host herptile (reptile and amphibian) migration routes that often pass active roadways. Mitigation strategies are not widely used. With turtles, there is a complication since they migrate throughout the year and so maintaining turtle tunnels year-round can be an issue. Conversely, salamanders are "explosive breeders" and will have a mass migration all at one time.

Riparian habitat

Wetlands and stream corridors are where most animals live, forage and seek water, which makes wetlands a priority site in terms of habitat restoration. There are many options for water-oriented habitat restoration. Restored riparian buffers provide additional habitat and migration routes. A major in-stream issue for aquatic habitat is shad migration.


Land development has broken up the natural habitats in Chester County. As a result, some animal species no longer have access to potentially viable habitat. Fragmentation of wildlife habitat also permits the introduction of invasive plant species, which do not always provide food for nesting for native animals. Utility corridors have a great potential to be used for native grasslands and meadow restoration. Because of national security concerns, there have been calls to upgrade some utility lines. These potential upgrades present an opportunity to properly restore the habitat around them as part of the upgrade process.

Water Quantity/The Water Balance

Stormwater, floodplains, surface water base flow, and ground water

Water providers are relying heavily on surface water intakes when the water balance would be better managed through tapping both surface and ground water supplies. Ground water wells remain as an important source of potable water in Chester County. As of 1998, 40 percent of the county's population received drinking water from ground water wells, but not all parts of the county have access to high yields. High yielding sedimentary and carbonate rock underlie just 10 percent of the county. There may be sufficient available ground water and surface water supplies to meet the public water supply needs of Chester County through 2020 and beyond; maintaining water quality is an issue.

Ongoing development is expected to continue to change the stormwater and flooding characteristics of the county and adapting to this will likely be labor intensive and costly.


Stormwater management is a major concern for municipalities. Often, the most recent developer to build within a community is expected to rectify stormwater problems that have accumulated over time. In Watersheds, reducing stormwater runoff is regarded as the highest management priority.

Stormwater issues are not fully understood by many municipal officials and planners, and there are insufficient mechanisms for explaining this complex topic to them.


The growth of impervious surfaces in Chester County has contributed to increased flooding events. The county's Department of Emergency Services has noticed an increase in water-related emergencies, along with flooding in areas that have never experienced it in the past. Stormwater-related flooding areas, such as Downingtown and Caln Township, are now experiencing greater floods, which is being attributed in part to development upstream.

Restoration programs

As areas with large unprotected open spaces have diminished, protected open spaces are becoming the last remaining areas for maintaining, enhancing, and restoring natural resources. Therefore, protected open spaces might serve as mitigation sites for natural communities, water quality, and air quality, or for locating projects that buffer climate change. Funding for preserving open spaces as natural resources is available, but limited.

Water purveyors transfer surface water from one watershed to another, which hampers efforts to promote adequate water volumes in stream. The amount of water flowing in the streams of Chester County is managed by various entities. Base flow does not rely solely on naturally occurring processes. Surface water quantity is a major regional issue since the Schuylkill, Susquehanna, Octoraro, and Brandywine are all being drawn upon as water sources. Chester County's streams are used as a water supply for both Chester County and all the surrounding counties. Also, private entities pump out water into streams, but when they close there is a reduction of the in-stream flow.

Water Quality/Pollution

Pollution sources, pollution from runoff, surface/ground water degradation, sewage discharge

Over a period of decades, nitrate and bacterial pollution has contaminated ground water supplies.

Nitrate and bacteria pollution

The number one ground water quality issue in Chester County is nitrate levels and bacteria pollution. Reversing this trend is a challenge because there are no state or county septic tank regulations; no requirements regarding pump-out; and nitrate removal systems are expensive. As a result, septic systems seep nitrates into the ground water, especially in rural municipalities and in the Octoraro Watershed. The problem is still not fully understood, but appears to be due to applied nutrients seeping deep into the ground water over a period of 30 to 40 years. Nitrates also impact surface waters. The Octoraro Creek is now on the impaired streams list, and nitrate concentration is the biggest issue. Nutrient removal systems are available, but they are expensive for both individual homeowners and large public systems.

Ground water pollution

Ground water and surface waters are hydrologically connected, and so pollution in one leads to pollution in the other. Because the Great Valley is underlain by limestone with solution cavities, its ground water is much more likely to be contaminated by surface water pollution. High nitrate levels in ground water are more common in agricultural communities where fertilizer or manure is applied to cropland. Elevated nitrate concentrations in ground water, such as in the Octoraro Watershed, could spur more public water service in rural areas.

There is no coordinated regional approach to improving designated impaired streams or addressing the pollution which caused their degradation.

Impaired streams

The state has listed 21 percent of Chester County's total stream miles as impaired. However, municipal planning often focuses on identifying Exceptional Value (EV) and High Quality (HQ) streams, but does not include measures to restore impaired streams. Currently there is a patchwork of specific water resource regulations in Chester County that may not cover all parts of the county.

Central planning needs

There is no entity empowered to do watershed-wide planning in Pennsylvania. It has been a struggle for public entities to coordinate all the processes of development while keeping water resources protected. While such organizations as the Delaware River Basin Commission (DRBC) promote growth management through water quality, utility, and land use planning, their primarily function is an advocate for the river, with less emphasis on the watershed as a whole.

Downstream impacts

Chester County has no single major river to rally public interest. As a result, there has been no push to create a unified, county-wide policy on streams. However, every municipality in the county is connected to at least one stream. The county has 1,306 miles of streams, 54 percent of which are "first order streams." The county's streams supply water for its eight downstream counties.

Inconsistent watershed preservation

Watershed management is inconsistent throughout the county partially because we are divided by two major watersheds, the Delaware and the Chesapeake. The Chesapeake Bay watershed programs are significantly different from the Delaware basin programs.

Exceptional Value and High Quality stream designations are becoming so common in some parts of the county that their value as a resource protection tool is becoming diluted. EV/HQ streams cover so much of Chester County that their protection value has become diminished. If an entire municipality is HQ/EV, then developers will be encouraged to build anywhere because all places will have an equal impact. The northern part of the county is so highly covered with EV streams that some foresee a situation where the few non-EV watersheds could become dumping grounds.

Emerging Issues

Technological advances, climate change, ongoing urbanization, and raised public expectations

Municipal environmental planning is oriented toward "green fields" development, but the focus on re-development has significant environmental impacts that are often unmanaged. From a natural resources perspective, all of Chester County needs to be managed as if it is an urbanized area. There are no untamed areas in Chester County. Previous county planning focused on environmentally sensitive development, but changes in the last decade have necessitated a new focus on redevelopment and restoring natural resources on existing property.

Funding and planning for forestry and tree planting is insufficient to accommodate anticipated changes relating to climate change and carbon sequestration. There is no comprehensive plan for managing climate change and carbon generation in the county. Identifying and implementing strategies is needed.

Innovative "green technologies" and "green planning techniques" need to be explored and implemented into municipal planning programs. Many new concepts in environmental planning have not yet been publicized to the general public. "Natural", "native", and "green" technologies have become a buzz words, but they get interpreted differently.
There are a number of expected new impacts to the environment for which there are few ways to currently measure or to realistically model their impacts. It is difficult to project the impacts of many developing technologies.

New water contaminants

In recent years, water quality has been impaired by new pharmaceuticals (including drugs and hormone treatments for humans, pets and livestock) and also by personal care products (such as shampoos and deodorants that can build up in septic tanks). There are currently no standards for measuring or reducing these contaminants.

Wildlife-human conflict

The increasing range of bears and bobcats north and west of Chester County is likely to increase the occurrence of young and potentially aggressive males being pushed into Chester County in search of territory, which could lead to more conflicts with humans.